What is the current state of the art in animal facial recognition?
In case of animal classification - trying to specify the animal, trying to tell cat from a dog - it should be similar to human faces. An algorithm such as SVM could be used in that case. Trying to tell two breeds of dog apart would be more challenging. I have come across this article explaining how they use facial recognition software for animals news. And I have also come across  this article where they write about a novel method for identifying individual cetaceans using facial features and symmetry on dolphins.